A conventional dual-bearing fishing reel as shown in FIG. 1 includes a reel body having a front wall 1 and a rear wall 2, a spool unit 3, a fishing line guiding mechanism (not shown), a drive device 5, and a brake unit 6. The spool unit 3 is rotatable relative to the reel body, and includes a spool rod 301, a spool hub 302 configured to permit a fishing line (not shown) to wind thereon, and a coupling sleeve 303 formed with a plurality of engaging teeth. The drive device 5 includes a shaft 501 mounted rotatably relative to the front wall 1, a main gear 502 coupled to rotate with the shaft 501 and configured to mesh with the engaging teeth of the coupling sleeve 303, and a hand-powered crank 503 coupled to drive the shaft 501 to rotate. The brake unit 6 is sleeved on the shaft 501, and includes two pressure discs 601, two friction discs 602, a clamping member 603, and a plurality of disk springs 604.
When the shaft 501 is driven by the hand-powered crank 503 to rotate, the spool unit 3 is driven by the main gear 502 to rotate. At the same time, a camshaft (not shown) of the fishing line guiding mechanism is driven by a secondary gear on the shaft 501 to rotate. In the fishing line guiding mechanism, a camming action between the camshaft and a cam follower of the fishing ling guiding mechanism will cause a linear reciprocating movement of a slider (not shown). The fishing line guided by the slider can be evenly wound on the spool hub 302.
In the above conventional dual-bearing fishing reel, rotational speed of the spool hub 302 cannot be varied.
U.S. Pat. No. 7,878,438 discloses another conventional dual-bearing fishing reel in which rotational speed of a spool hub can be varied by pushing or pulling of an operation shaft.
U.S. Pat. No. 8,480,020 discloses a traverse camshaft of a fishing reel. In addition, as disclosed in US publication nos. 20160106082 and 20170064934, the inventor of this application also proposed an adjusting unit for varying rotation speed of a spool hub.